长骨内开口效应对其力学性能影响的理论模型研究

建立一个股骨中段的外侧皮质带有矩形开口的力学模型,采用有限元方法,计算骨开口区的尺寸改变时,股骨的扭转刚度和应力分布的变化。结果表明:骨开口长度为骨外径的1倍时(1OD),对股骨扭转刚度和剪应力分布的影响较小;开口长度从2OD增至4OD时扭转刚度急剧减小,而且剪应力的最大值位于开口区中心。本结论对临床骨科的手术治疗方法和骨开口尺寸的控制提供了重要的理论依据。     

Influence of perinatal malnutrition on adult physiological and behavioral reactivity in rats

A series of experiments examined the behavioral and pituitary-adrenal response to novelty of perinatally malnourished rats tested as adults after nutritional rehabilitation begun at weaning. Neither the behavioral measures of ambulation, rearing and defecation, nor the plasma corticosterone response to a brief exposure to an open field differentiated the previously malnourished subjects from controls. Similar to controls, previously malnourished subjects were also capable of displaying a graded corticoid elevation to environments increasingly different from the home cage. However, exploratory behavior, as measured by head-dip frequency and duration in the hole-board, was reduced in the previously malnourished rats. Although latency and amount of fluid consumed in a novel environment did not differ, previously malnourished rats were unable to use the cues associated with a consummatory behavior to modulate the pituitary-adrenal response to novelty. Thus, perinatal malnutrition does not influence either the behavioral or physiological activational response to novel stimulation but appears to alter the ability of the animal to use a consummatory behavior to modulate this response.     

Dual effect of temperature on the human epithelial Na+ channel

The amiloride-sensitive epithelial sodium channel (ENaC) is the rate-limiting step for sodium reabsorption in the distal segments of the nephron, in the colon and in the airways. Its activity is regulated by intracellular and extracellular factors but the mechanisms of this regulation are not yet completely understood. Recently, we have shown that the fast regulation of ENaC by the extracellular [Na⁺], a phenomenon termed self-inhibition, is temperature dependent. In the present study we examined the effects of temperature on the single-channel properties of ENaC. Single-channel recordings from excised patches showed that the channel open probability (P _o, estimated from the number of open channels N·P _o, where N is the total number of channels) increased on average two- to threefold while the single-channel conductance decreased by about half when the temperature of the perfusion solution was lowered from ~30 to ~15 °C. The effects of temperature on the single-channel conductance and P _o explain the changes of the macroscopic current that can be observed upon temperature changes and, in particular, the paradoxical effect of temperature on the current carried by ENaC.     

Angiomyomatous hamartoma and associated stromal lesions in the right inguinal lymph node: a case report

Angiomyomatous hamartoma is a rare disease with a predisposition for the inguinal lymph nodes. A 51-year-old male patient visited a local hospital because of a right inguinal mass, measuring 3 x 4 cm in size, which was resected. The resected specimen showed irregularly distributed thick-walled vessels in the hilum, extending into the medulla and focally into the cortex of the node, eventually becoming more dispersed and associated with smooth muscle cells splaying into sclerotic stroma. These findings are compatible with an angiomyomatous hamartoma. Another tumor-like mass appeared shortly after the resection at the same location, but was not an angiomyomatous hamartoma, rather it was composed of edematous stromal tissue with proliferating smooth muscle cells. The stromal component included thick-walled blood vessels and lymphatics. Although it could not be determined whether these associated changes in the surrounding stroma are a cause or an effect of angiomyomatous hamartoma, they indicate the clinical difficulty in determining an appropriate area of resection and may provide clues to the pathogenesis of angiomyomatous hamartoma.     

The time-course of ribavirin-provoked changes of basal and AMPH-induced motor activities in rats

The time-course of changes of basal and amphetamine (AMPH)-induced locomotor and stereotypic activities in adult male Wistar rats after a single ribavirin injection was studied. In the first set of experiments, 10, 20 or 30 mg ribavirin/kg body weight (b.w.) were injected i.p. to rats and their basal motor activities were recorded every 10 min for 2 h and compared with those of saline-treated controls. In the second set of experiments, the animals were pretreated with ribavirin and 20 min later i.p. injected with AMPH (1.5 mg/kg b.w.). The controls received AMPH 20 min after the saline injection. Motor activity was recorded after the first injection and until 120 min after AMPH administration. Ribavirin did not significantly affect the time-course of either basal locomotor or stereotypic activities. Pretreatment with any of the applied ribavirin doses decreased the AMPH-induced hyperlocomotor response. However, the most pronounced effect was observed with ribavirin doses of 20 mg/kg and 30 mg/kg when administered during the first 10 min and 30 min after the AMPH injection respectively. In contrast, the stereotypic activities of these animals were only slightly changed. These results indicate a different susceptibility of regions in the basal ganglia to ribavirin.     

异种脱细胞真皮基质在开放性乳突病变切除术中的应用

目的探讨开放性乳突病变切除术后加速乳突术腔上皮化及缩小乳突术腔的有效办法。方法63例行开放性乳突病变切除术的患者按照复查治疗方法分为两组，异种脱细胞真皮组36例，应用异种脱细胞真皮基质覆盖术腔，碘仿纱条组27例，以碘仿纱条填塞术腔。术后随访两组患者，对比观察术腔愈合情况和上皮化时间。结果异种脱细胞真皮组术腔上皮化时间为2～4周，平均2．2周；碘仿纱条组术腔上皮化时间为9～35周，平均13．7周，异种脱细胞真皮组的上皮化时间短于碘仿纱条组（P〈0．01）。结论异种脱细胞真皮基质可促进上皮组织再生，减少术后感染及肉芽发生，加速乳突腔上皮化，提高开放性乳突病变切除术的疗效。     

Physiological and behavioral effects of prior aversive stimulation (preshock) in the rat

Physiological and behavioral measures were assessed in rats that had been previously exposed to unsignaled inescapable intense shock (preshock). Animals subjected to such prior aversive stimulation exhibited greater adrenocortical steroid response compared to nonpreshocked controls when subsequently tested in the open field. An increment in defecation was also observed, with ambulation and rearing behavior being markedly inhibited in the preshocked rat during these sessions.     

Chlorimipramine,electroconvulsive shock and combination thereof: Differential effects of chronic treatment on apomorphine-induced behaviours and on striatal and mesocortical dopamine turnover

Summary We studied the influence of different pretreatment regimens (Chlorimipramine-Cmi, electroconvulsive shock-ECS, and Cmi+ECS all regimens being applied for either 2 or 15 days) on the open field behaviour, on the striatal and on the prefrontal dopamine-PFC DA turnover in rats injected with either apomorphine-AP 25 g/kg (stimulating presynaptic DA receptors), AP 200 g/kg (stimulating postsynaptic DA receptors), or vehicle (control).In the controls, AP 25 g/kg reduced the locomotor activity and the striatal, but not the PFC DA turnover. AP 200 g/kg increased the locomotor activity and reduced the striatal but not the PFC DA turnover.Short-term pretreatment: ECS and Cmi+ECS prevented the decrease of striatal DA turnover after AP 25 g/kg. No other influence of any pretreatment on behaviour or DA-turnover became significant.Long-term pretreatment: Chronic Cmi: marginally increased the open field behaviour and marginally decreased the PFC DA turnover; significantly increased the effect of AP (200 g/kg) on striatal DA turnover and the effect of AP (25 and 200 g/kg) on PFC DA turnover. Repeated ECS: decreased locomotion and rearing and increased PFC DA turnover; increased the effect of AP (200 g/kg) on locomotion and on striatal DA turnover; decreased the effect of AP (25 and 200 g/kg) on PFC DA turnover.Chronic Cmi+ECS: decreased locomotion and rearing and marginally decreased PFC DA turnover; increased the effect of AP on hyperlocomotion and on striatal DA turnover. No other influence of any chronic pretreatment on behaviour or on DA turnover became significant.The data support the view that chronic AD therapies increase DAergic functions related to postsynaptic rather than to presynaptic structures. It is suggested that the different effects of chronic Cmi and repeated ECS on AP-evoked PFC DA turnover help to understand the different influences exerted by both treatments on rats' behaviour.     

腹腔镜手术与传统手术治疗小儿腹股沟斜疝

目的探析腹腔镜与传统手术治疗小儿腹股沟斜疝的临床效果。方法集合本院2016年1月-2019年9月期间接收小儿腹股沟斜疝(年龄<13周岁)234例,以实际治疗术式来分组,传统手术组201例,腹腔镜组33例,对比组行传统手术,腹腔镜组予以腹腔镜手术治疗,对比两组术中失血量、住院时间、初次下床活动时间、术后禁食时长、治疗费用,统计术后并发症并行组间对比。结果此次研究显示腹腔镜组术中失血量更少、术后禁食时长及初次下床活动时间更短(P<0.05),住院时间及、治疗费用组间对照中,腹腔镜组住院时间显著更短但治疗费用显著更高(P<0.05),术后并发症统计显示,腹腔镜组并发症发生率显著更低(P<0.05)。结论在小儿腹股沟斜疝治疗中腹腔镜手术虽费用较高,但患儿术后并发症更少,恢复更快,可优先选用。     

COVID-19对学术交流的影响及学术出版机构的应对举措

【目的】 研究COVID-19疫情暴发给学术交流及学术出版带来的深远影响。【方法】 利用文献调研法和案例分析法挖掘COVID-19疫情带来的学术环境变化,并探讨学术出版的整体变化趋势和国内外出版机构的应对方式。【结果】 COVID-19疫情改变了当前的学术交流环境:加速推进开放科学进程,快速传播的预出版模式受到青睐,开放评审促进快速学术交流,多项基金项目助力COVID-19科学研究,中国科研人员应对COVID-19反应积极而迅速。出版机构顺应学术出版的整体趋势,为科学共同体提供大量免费服务,扩大知识服务的目标群体,提供海量知识及COVID-19快速发表通道,我国出版机构应对COVID-19也采取了大量积极举措。【结论】 国内外出版机构应对突发事件时应建立学术出版应急机制,增强知识服务能力,促进知识创新及传播,以适应一个全新的快速发展的学术环境。